Boston researchers announced today the results of one of the biggest medical advancements in breast cancer treatment to come along in decades. Breast cancer treatment studies have found the drug Herceptin cuts the risk in half that women with a rapidly growing type of breast tumor would experience a relapse. The incredible success of this breast cancer treatment also marks an innovative approach to cancer treatment. Experts are beginning to believe that drugs which target one specific genetic mutation will be more beneficial than broad therapies.
“The results are simply stunning,” reports Dr. Gabriel Hortobagyi, a leading oncologist, whose editorial appeared along side this exciting research in October’s New England Journal of Medicine. Doctors say that it is rare for a drug to show such strong results. Typically, a drug is considered successful if it can extend a patient’s life for even a short time. Herceptin shows the strongest results of any breast cancer treatment since Tamoxifen. Tamoxifen is a drug used to reduce the risk of relapse in patients with estrogen-positive breast cancer.
The two breast cancer studies, one based in the US and one in Europe, focused on women with a particular type of breast cancer. Fifteen to twenty percent of all breast cancer patients have a genetic mutation called HER-2 positive. This type of breast cancer is remarkably aggressive and resistant to treatment. One in three patients with this type of breast cancer experiences a relapse, most of which are fatal.
In these studies, patients with this aggressive recurrent cancer were given Herceptin after surgery in the early stages of HER-2 positive breast cancer. When combined with standard chemotherapy, Herceptin drastically reduced the risk that breast cancer would return.
The results of this study were so mind-blowing that, half way through the study, the patients in the placebo group were offered Herceptin. Doctors began prescribing this drug to their early-stage HER-2 positive breast cancer patients in May, after the preliminary results of these studies were presented.
The California-based pharmaceutical company, Genentech, says their sales of this drug increased seventy percent between July and September 2005. Genentech and the National Cancer Institute sponsored the US-based study. Roche, Herceptin’s maker in Europe, sponsored the European study.
While this drug has proved the most promising new breast cancer treatment to be discovered in decades, it is not without risk. In the US-based trial, approximately four percent of women taking Herceptin developed cardiovascular side effects. Congestive heart failure, a condition which gradually weakens the heart over time, is one of the primary side effects experienced by this small patient population. Researchers are further investigating these risks.